163 replies to this topic

[videodan]

I just got finished diving (and watching my tape on a 50" HDTV) with an Expodisc installed in my housing, and all I can say is wow! This is a must have for anyone who uses manual white balance, and can fit one in their housing. I have the L&M Bluefin HD with FX1, and butchered up an Expodisc to fit in the close up lens flip arm. It was pretty easy to do. Note:The Expodisc cannot be exposed to water, so it must go in the housing, unless they design one for external use. They told me I would be the first to try one underwater, and they weren't sure if it would work well. Well I'll tell you now, that it works better than well. I dove today to 85', and tried manual white balance with and without the Expodisc. I frequently have difficulty getting the MWB to lock at those depths, including today. I usually blinks many times before it will lock, and quite often will not lock at all. When I tried with the Expodisc, it blinked once, and locked immediately, every time I used it, no matter what I aimed it at. I could tell right away looking in the monitor, that the colors were absolutely perfect every time. Watching on a Sony 50" HDTV proved it. There was excellent color saturation, color accuracy, and color balance. Everyone watching was amazed at how all the various colored small fishes in a big school all stood out. The reds have never looked better, definitely not overpowering, the yellows showed more than ever before, but still not too much, and the blues were beautiful. BTW, today was a mediocre dive day in South Florida. Heavy, dark overcast all day, and 40-50' vis at best, with a lot of particulates in the water. The Expodisc works by diffusing and mixing the available light, and passes through as 18% Grey. It really is amazing how well it worked, and I'm going back out tomorrow to use it again as it's supposed to be sunnier than today. I'm sure going to miss that close up lens, but Expodisc sure makes up for it. Btw, I am in no way affiliated with Expodisc, just a very satisfied user.

[videodan]

Good news, Expodisc is discussing the possibility of producing a waterproof underwater version that anybody can use. I certainly hope they do. Here's a great article on "Understanding White Balance" which also mentions the Expodisc. Below are pictures showing my installation. BTW, I should mention that you manually white balance simultaneously through the Expodisc in front of a Color Correction Filter, and then remove the Expodisc and shoot through just the CC Filter.

[MikeVeitch]

Interesting Dan..

will look into it, thanks for heads up

[wagsy]

What a great idea Dan and well done on the feedback.

WB at depth can sometimes be a problem as well here however there are many times were I don't want it a true WB to maybe blue up the water or warm up a certain shot more so.

I' see we can get them in Aus as well, I'l go and get one.

[Nick Hope]

So we really need a 3rd flip arm now

Thanks for the idea Dan. Will get one to try.

I wonder how this would work at night, averaging out the light of an artifically lit scene.

And I wonder if you could run the Epodisc in combination with the flip macro and leave out the Ur-Pro filter for night/cave diving. How quick are those arms to change on the Bluefin and are they interchangable?

By the way if my VX2000 won't white balance at depth I just point it at or near the sun and it always performs a white balance. I guess the extra luminance makes WB easier for the camera to perform.

Nick

[videodan]

Wagsy, you'll love it. The colors come out very saturated and intense. Best looking colors I've seen, and MWB is quick.
Nick, should work great at night, as it diffuses and blends all the light, even from mixed sources, for a perfect white balance. My TRV900 would lock WB at any depth up to 145', but the FX1 it a lot pickier, and is often difficult to set. Even when the cameras lock WB, sometimes the WB is all wrong. I tried stopping down, zooming, out of focus, full manual, etc., and nothing seemed to work, it just kept on blinking. The Expodisc fixed all my WB issues. Also, try it topside in difficult situations, thats what made me think it would be good underwater.

And I wonder if you could run the Epodisc in combination with the flip macro and leave out the Ur-Pro filter for night/cave diving. How quick are those arms to change on the Bluefin and are they interchangable?

It should work fine, and no the flip arms are not interchangeable, but they both remove easily.

[wagsy]

Okay you have me..I'll get one.

Could work out good as I have the colour filter always on the end of the camera now and the first flip arm has the macro +2 so I can put the 67 Expodisc on the outer flip arm..bingo all three.

AUS SHOP EXPODISC HERE

These guys have a nice 67 mm one that should go straight on for $148 AUS..will order on Monday...

[Nick Hope]

Wagsy, room for a colour filter screwed on the camera and 2 loaded flip arms? And all this behind the reworked Amphibico lens? How did you manage that? Have you whittled them all down to the thickness of a nat's todger or what?

[videodan]

Day two with Expodisc, and I'm 100% sold on it. Diving was far worse, 30' vis, very dark overcast and rain with no sun whatsoever, very murky, and diving to 85' deep. I'm watching the video now as I type, and the colors are absolutely fabulous, unbelieveable in fact for the conditions. The colors seem very balanced, but just all seem to stand out. Awesome. Tried to do some before and after shots, but without Expodisc, I couldn't set the MWB. I've been shooting underwater for many years, and I've never had video look this good under these conditions. Wagsy, I cut up a 77mm Expodisc as it closely matched the width of my flip lens. I'm sure you will need to remove the filter elements from the filter mount, as it may be too thick otherwise. There are three individual filter elements, so you will need to tape or glue (outside edges recommended) them together. The upcoming Bluefin HD UWA lens extends deeper into the housing, so I will be remounting the Expodisc onto the CC Filter arm, and use a fixed CC Filter on the camera. Can't wait to hear from others who install this fantastic white balance filter, and will immediately love it. I knew as soon as I first set my white balance and looked in the monitor.

[wagsy]

Good work Dan, sounds like it realy does help. Can you post a screen grab of the colour you got.

I'll put my order for a round 67mm one tomorrow (MON). Should go straight on the flip arm.

Nick I would have to use the old lens to have all three. New shaved port only allows one flip arm. Filter on always works fine for tropical diving.

Dan, so you are going got loose a flip arm as well....yep vignetting I would say made them do that. 16.9 really goes wide for ports.

[Steve Douglas]

I never heard of this expodisc. Is there a url to where it is sold? Just got back from the Philippines and also had a few times where MWB was a bit difficult.
Steve B)

[Nick Hope]

http://www.expoimaging.net

http://www.bhphotovi...arch&Q=&ci=9630

Dan, with the 80-degree lens you have now do you think it would be possible to retain the flip macro lens, mount the Expodisc in the CC flip arm, and have a CC filter screwed straight on the camera? If not then with a gel CC filter on the camera perhaps?

Nick

[videodan]

Dan, so you are going got loose a flip arm as well....yep vignetting I would say made them do that. 16.9 really goes wide for ports.

Yes, with the UWA lens we'll lose the front flip arm due to the lens extending deeper into the housing. Just ordered my 72mm URPro CC Filter to put on camera. The expodisc is staying in my housing no matter what I have to do.

I never heard of this expodisc. Is there a url to where it is sold?

They are available at most camera shops. Expodisc website is: http://www.expoimaging.net/products/ It is unbelieveable how good, and how fast you can set the MWB with the Expodisc. Try it on your video or still camera in mixed or difficult lighting. That's how I figured it would work well underwater. I too, often had difficulty setting proper MWB at depth underwater with my FX1, if I could set it at all. Not a problem anymore. Wait a few days till others (Wagsy, etc.) try it. I guarantee he'll agree with me.

[videodan]

Dan, with the 80-degree lens you have now do you think it would be possible to retain the flip macro lens, mount the Expodisc in the CC flip arm, and have a CC filter screwed straight on the camera? If not then with a gel CC filter on the camera perhaps?

I'm sure you can mount the Expodisc on the CC Filter arm (as I'm going to do next). I have a screw on filter ordered, so I'll get back to you then. The Expodisc (three elements combined) after removing it from the filter holder is just about exactly 1/4" (.250") thick, it that helps you at all.

[wagsy]

Hi Guys
Dan, if you screw the filter on the end of the camera it will stop the flip arm...
It needs to sit inside the end of the camera so it's flush, I used a 67mm ring that fits right in. I put some soft tape around the edge so the ring sits in there snug. It cannot be screw in...

[RebreatherDave]

So it looks like one is supposed to flip down the Expodisc, white balance, then flip it back out of the way?

[videodan]

Dan, if you screw the filter on the end of the camera it will stop the flip arm...

Is that on the Phenom, or the Bluefin HD?

So it looks like one is supposed to flip down the Expodisc, white balance, then flip it back out of the way?

Yes, the Expodisc must be placed in front of the CC Filter and manually white balanced, then remove the Expodisc and shoot video. It is only for white balancing.

[videodan]

Here are some frame grabs as requested. These are not representative of good pictures, rather they are to show the white balance acheived at depth with Expodisc under really crappy dive conditions.

Diving was far worse, 30' vis, very dark overcast and rain with no sun whatsoever, very murky, and diving to 85' deep.

Notice the diver in the background on the first picture to see how murky it was. These photos were not enhanced to look better on a computer monitor, and they look far better on an HDTV than they do on a computer. These are straight frame grabs to jpeg.

[Nick Hope]

Looks good to me Dan. Very natural. Are those on full wide?

Wags, not quite with you on this 67mm ring. Did you fit the Ur-pro filter from your flip arm into an empty 67mm filter ring? Did you have to remove any of the 67mm threaded bit of ring to get it to sit flush with the front of the camera? No vignetting from the ring? (apologies for the dreaded "v" word yet again)

[Steve Douglas]

Has anyone found one that would fit an A1-U and Gates housing?
Steve B)